Commit Graph

387 Commits

Author SHA1 Message Date
Benno Lossin
38cde0bd7b rust: init: add Zeroable trait and init::zeroed function
Add the `Zeroable` trait which marks types that can be initialized by
writing `0x00` to every byte of the type. Also add the `init::zeroed`
function that creates an initializer for a `Zeroable` type that writes
`0x00` to every byte.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-12-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
6841d45a30 rust: init: add stack_pin_init! macro
The `stack_pin_init!` macro allows pin-initializing a value on the
stack. It accepts a `impl PinInit<T, E>` to initialize a `T`. It allows
propagating any errors via `?` or handling it normally via `match`.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230408122429.1103522-11-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
d0fdc39612 rust: init: add PinnedDrop trait and macros
The `PinnedDrop` trait that facilitates destruction of pinned types.
It has to be implemented via the `#[pinned_drop]` macro, since the
`drop` function should not be called by normal code, only by other
destructors. It also only works on structs that are annotated with
`#[pin_data(PinnedDrop)]`.

Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-10-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
92c4a1e7e8 rust: init/sync: add InPlaceInit trait to pin-initialize smart pointers
The `InPlaceInit` trait that provides two functions, for initializing
using `PinInit<T, E>` and `Init<T>`. It is implemented by `Arc<T>`,
`UniqueArc<T>` and `Box<T>`.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-9-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
fc6c6baa1f rust: init: add initialization macros
Add the following initializer macros:
- `#[pin_data]` to annotate structurally pinned fields of structs,
  needed for `pin_init!` and `try_pin_init!` to select the correct
  initializer of fields.
- `pin_init!` create a pin-initializer for a struct with the
  `Infallible` error type.
- `try_pin_init!` create a pin-initializer for a struct with a custom
  error type (`kernel::error::Error` is the default).
- `init!` create an in-place-initializer for a struct with the
  `Infallible` error type.
- `try_init!` create an in-place-initializer for a struct with a custom
  error type (`kernel::error::Error` is the default).

Also add their needed internal helper traits and structs.

Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-8-y86-dev@protonmail.com
[ Fixed three typos. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
90e53c5e70 rust: add pin-init API core
This API is used to facilitate safe pinned initialization of structs. It
replaces cumbersome `unsafe` manual initialization with elegant safe macro
invocations.

Due to the size of this change it has been split into six commits:
1. This commit introducing the basic public interface: traits and
   functions to represent and create initializers.
2. Adds the `#[pin_data]`, `pin_init!`, `try_pin_init!`, `init!` and
   `try_init!` macros along with their internal types.
3. Adds the `InPlaceInit` trait that allows using an initializer to create
   an object inside of a `Box<T>` and other smart pointers.
4. Adds the `PinnedDrop` trait and adds macro support for it in
   the `#[pin_data]` macro.
5. Adds the `stack_pin_init!` macro allowing to pin-initialize a struct on
   the stack.
6. Adds the `Zeroable` trait and `init::zeroed` function to initialize
   types that have `0x00` in all bytes as a valid bit pattern.

--

In this section the problem that the new pin-init API solves is outlined.
This message describes the entirety of the API, not just the parts
introduced in this commit. For a more granular explanation and additional
information on pinning and this issue, view [1].

Pinning is Rust's way of enforcing the address stability of a value. When a
value gets pinned it will be impossible for safe code to move it to another
location. This is done by wrapping pointers to said object with `Pin<P>`.
This wrapper prevents safe code from creating mutable references to the
object, preventing mutable access, which is needed to move the value.
`Pin<P>` provides `unsafe` functions to circumvent this and allow
modifications regardless. It is then the programmer's responsibility to
uphold the pinning guarantee.

Many kernel data structures require a stable address, because there are
foreign pointers to them which would get invalidated by moving the
structure. Since these data structures are usually embedded in structs to
use them, this pinning property propagates to the container struct.
Resulting in most structs in both Rust and C code needing to be pinned.

So if we want to have a `mutex` field in a Rust struct, this struct also
needs to be pinned, because a `mutex` contains a `list_head`. Additionally
initializing a `list_head` requires already having the final memory
location available, because it is initialized by pointing it to itself. But
this presents another challenge in Rust: values have to be initialized at
all times. There is the `MaybeUninit<T>` wrapper type, which allows
handling uninitialized memory, but this requires using the `unsafe` raw
pointers and a casting the type to the initialized variant.

This problem gets exacerbated when considering encapsulation and the normal
safety requirements of Rust code. The fields of the Rust `Mutex<T>` should
not be accessible to normal driver code. After all if anyone can modify
the fields, there is no way to ensure the invariants of the `Mutex<T>` are
upheld. But if the fields are inaccessible, then initialization of a
`Mutex<T>` needs to be somehow achieved via a function or a macro. Because
the `Mutex<T>` must be pinned in memory, the function cannot return it by
value. It also cannot allocate a `Box` to put the `Mutex<T>` into, because
that is an unnecessary allocation and indirection which would hurt
performance.

The solution in the rust tree (e.g. this commit: [2]) that is replaced by
this API is to split this function into two parts:

1. A `new` function that returns a partially initialized `Mutex<T>`,
2. An `init` function that requires the `Mutex<T>` to be pinned and that
   fully initializes the `Mutex<T>`.

Both of these functions have to be marked `unsafe`, since a call to `new`
needs to be accompanied with a call to `init`, otherwise using the
`Mutex<T>` could result in UB. And because calling `init` twice also is not
safe. While `Mutex<T>` initialization cannot fail, other structs might
also have to allocate memory, which would result in conditional successful
initialization requiring even more manual accommodation work.

Combine this with the problem of pin-projections -- the way of accessing
fields of a pinned struct -- which also have an `unsafe` API, pinned
initialization is riddled with `unsafe` resulting in very poor ergonomics.
Not only that, but also having to call two functions possibly multiple
lines apart makes it very easy to forget it outright or during refactoring.

Here is an example of the current way of initializing a struct with two
synchronization primitives (see [3] for the full example):

    struct SharedState {
        state_changed: CondVar,
        inner: Mutex<SharedStateInner>,
    }

    impl SharedState {
        fn try_new() -> Result<Arc<Self>> {
            let mut state = Pin::from(UniqueArc::try_new(Self {
                // SAFETY: `condvar_init!` is called below.
                state_changed: unsafe { CondVar::new() },
                // SAFETY: `mutex_init!` is called below.
                inner: unsafe {
                    Mutex::new(SharedStateInner { token_count: 0 })
                },
            })?);

            // SAFETY: `state_changed` is pinned when `state` is.
            let pinned = unsafe {
                state.as_mut().map_unchecked_mut(|s| &mut s.state_changed)
            };
            kernel::condvar_init!(pinned, "SharedState::state_changed");

            // SAFETY: `inner` is pinned when `state` is.
            let pinned = unsafe {
                state.as_mut().map_unchecked_mut(|s| &mut s.inner)
            };
            kernel::mutex_init!(pinned, "SharedState::inner");

            Ok(state.into())
        }
    }

The pin-init API of this patch solves this issue by providing a
comprehensive solution comprised of macros and traits. Here is the example
from above using the pin-init API:

    #[pin_data]
    struct SharedState {
        #[pin]
        state_changed: CondVar,
        #[pin]
        inner: Mutex<SharedStateInner>,
    }

    impl SharedState {
        fn new() -> impl PinInit<Self> {
            pin_init!(Self {
                state_changed <- new_condvar!("SharedState::state_changed"),
                inner <- new_mutex!(
                    SharedStateInner { token_count: 0 },
                    "SharedState::inner",
                ),
            })
        }
    }

Notably the way the macro is used here requires no `unsafe` and thus comes
with the usual Rust promise of safe code not introducing any memory
violations. Additionally it is now up to the caller of `new()` to decide
the memory location of the `SharedState`. They can choose at the moment
`Arc<T>`, `Box<T>` or the stack.

--

The API has the following architecture:
1. Initializer traits `PinInit<T, E>` and `Init<T, E>` that act like
   closures.
2. Macros to create these initializer traits safely.
3. Functions to allow manually writing initializers.

The initializers (an `impl PinInit<T, E>`) receive a raw pointer pointing
to uninitialized memory and their job is to fully initialize a `T` at that
location. If initialization fails, they return an error (`E`) by value.

This way of initializing cannot be safely exposed to the user, since it
relies upon these properties outside of the control of the trait:
- the memory location (slot) needs to be valid memory,
- if initialization fails, the slot should not be read from,
- the value in the slot should be pinned, so it cannot move and the memory
  cannot be deallocated until the value is dropped.

This is why using an initializer is facilitated by another trait that
ensures these requirements.

These initializers can be created manually by just supplying a closure that
fulfills the same safety requirements as `PinInit<T, E>`. But this is an
`unsafe` operation. To allow safe initializer creation, the `pin_init!` is
provided along with three other variants: `try_pin_init!`, `try_init!` and
`init!`. These take a modified struct initializer as a parameter and
generate a closure that initializes the fields in sequence.
The macros take great care in upholding the safety requirements:
- A shadowed struct type is used as the return type of the closure instead
  of `()`. This is to prevent early returns, as these would prevent full
  initialization.
- To ensure every field is only initialized once, a normal struct
  initializer is placed in unreachable code. The type checker will emit
  errors if a field is missing or specified multiple times.
- When initializing a field fails, the whole initializer will fail and
  automatically drop fields that have been initialized earlier.
- Only the correct initializer type is allowed for unpinned fields. You
  cannot use a `impl PinInit<T, E>` to initialize a structurally not pinned
  field.

To ensure the last point, an additional macro `#[pin_data]` is needed. This
macro annotates the struct itself and the user specifies structurally
pinned and not pinned fields.

Because dropping a pinned struct is also not allowed to break the pinning
invariants, another macro attribute `#[pinned_drop]` is needed. This
macro is introduced in a following commit.

These two macros also have mechanisms to ensure the overall safety of the
API. Additionally, they utilize a combined proc-macro, declarative macro
design: first a proc-macro enables the outer attribute syntax `#[...]` and
does some important pre-parsing. Notably this prepares the generics such
that the declarative macro can handle them using token trees. Then the
actual parsing of the structure and the emission of code is handled by a
declarative macro.

For pin-projections the crates `pin-project` [4] and `pin-project-lite` [5]
had been considered, but were ultimately rejected:
- `pin-project` depends on `syn` [6] which is a very big dependency, around
  50k lines of code.
- `pin-project-lite` is a more reasonable 5k lines of code, but contains a
  very complex declarative macro to parse generics. On top of that it
  would require modification that would need to be maintained
  independently.

Link: https://rust-for-linux.com/the-safe-pinned-initialization-problem [1]
Link: 0a04dc4ddd [2]
Link: f509ede33f/samples/rust/rust_miscdev.rs [3]
Link: https://crates.io/crates/pin-project [4]
Link: https://crates.io/crates/pin-project-lite [5]
Link: https://crates.io/crates/syn [6]
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-7-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
3ff6e785ad rust: types: add Opaque::raw_get
This function mirrors `UnsafeCell::raw_get`. It avoids creating a
reference and allows solely using raw pointers.
The `pin-init` API will be using this, since uninitialized memory
requires raw pointers.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-6-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
d6dbca3592 rust: sync: change error type of constructor functions
Change the error type of the constructors of `Arc` and `UniqueArc` to be
`AllocError` instead of `Error`. This makes the API more clear as to
what can go wrong when calling `try_new` or its variants.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230408122429.1103522-4-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Gary Guo
70a21e54a4 rust: macros: add quote! macro
Add the `quote!` macro for creating `TokenStream`s directly via the
given Rust tokens. It also supports repetitions using iterators.

It will be used by the pin-init API proc-macros to generate code.

Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-3-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
2d19d369c0 rust: enable the pin_macro feature
This feature enables the use of the `pin!` macro for the `stack_pin_init!`
macro. This feature is already stabilized in Rust version 1.68.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-2-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Wedson Almeida Filho
ef4dc4cc70 rust: error: Add from_result() helper
Add a helper function to easily return C result codes from a Rust function
that calls functions which return a Result<T>.

Lina: Imported from rust-for-linux/rust, originally developed by Wedson
as part of file_operations.rs. Added the allow() flags since there is no
user in the kernel crate yet and fixed a typo in a comment. Replaced the
macro with a function taking a closure, per discussion on the ML.

Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-6-03779bddc02b@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Sven Van Asbroeck
752417b3f0 rust: error: Add a helper to convert a C ERR_PTR to a Result
Some kernel C API functions return a pointer which embeds an optional
`errno`. Callers are supposed to check the returned pointer with
`IS_ERR()` and if this returns `true`, retrieve the `errno` using
`PTR_ERR()`.

Create a Rust helper function to implement the Rust equivalent:
transform a `*mut T` to `Result<*mut T>`.

Lina: Imported from rust-for-linux/linux, with subsequent refactoring
and contributions squashed in and attributed below. Renamed the function
to from_err_ptr().

Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-5-03779bddc02b@asahilina.net
[ Add a removal of `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Wedson Almeida Filho
086fbfa3b3 rust: error: Add to_result() helper
Add a to_result() helper to convert kernel C return values to a Rust
Result, mapping >=0 values to Ok(()) and negative values to Err(...),
with Error::from_errno() ensuring that the errno is within range.

Lina: Imported from rust-for-linux/rust, originally developed by Wedson
as part of the AMBA device driver support.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-4-03779bddc02b@asahilina.net
[ Add a removal of `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Miguel Ojeda
6551a7fe0a rust: error: Add Error::from_errno{_unchecked}()
Add a function to create `Error` values out of a kernel error return,
which safely upholds the invariant that the error code is well-formed
(negative and greater than -MAX_ERRNO). If a malformed code is passed
in, it will be converted to EINVAL.

Lina: Imported from rust-for-linux/rust as authored by Miguel and Fox
with refactoring from Wedson, renamed from_kernel_errno() to
from_errno().

Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-3-03779bddc02b@asahilina.net
[ Mark the new associated functions as `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Asahi Lina
c7e20faa5f rust: error: Add Error::to_ptr()
This is the Rust equivalent to ERR_PTR(), for use in C callbacks.
Marked as #[allow(dead_code)] for now, since it does not have any
consumers yet.

Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-2-03779bddc02b@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Asahi Lina
46384d0990 rust: error: Rename to_kernel_errno() -> to_errno()
This is kernel code, so specifying "kernel" is redundant. Let's simplify
things and just call it to_errno().

Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-1-03779bddc02b@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Asahi Lina
31d95c2f99 rust: sync: arc: Add UniqueArc<MaybeUninit<T>::assume_init()
We can already create `UniqueArc<MaybeUninit<T>>` instances with
`UniqueArc::try_new_uninit()` and write to them with `write()`. Add
the missing unsafe `assume_init()` function to promote it to
`UniqueArc<T>`, so users can do piece-wise initialization of the
contents instead of doing it all at once as long as they keep the
invariants (the same requirements as `MaybeUninit::assume_init()`).

This mirrors the std `Arc::assume_init()` function. In the kernel,
since we have `UniqueArc`, arguably this only belongs there since most
use cases will initialize it immediately after creating it, before
demoting it to `Arc` to share it.

[ Miguel: The "Rust pin-init API for pinned initialization of structs"
  patch series [1] from Benno Lossin contains a very similar patch:

    rust: sync: add `assume_init` to `UniqueArc`

    Adds the `assume_init` function to `UniqueArc<MaybeUninit<T>>` that
    unsafely assumes the value to be initialized and yields a value of type
    `UniqueArc<T>`. This function is used when manually initializing the
    pointee of an `UniqueArc`.

  To make that patch a noop and thus drop it, I adjusted the `SAFETY`
  comment here to be the same as in the current latest version of
  that series (v7).

  I have also brought the `Reviewed-by`s there into here, and reworded
  the `Co-authored-by` into `Co-developed-by`. ]

Link: https://lore.kernel.org/r/20230408122429.1103522-5-y86-dev@protonmail.com [1]
Co-developed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230224-rust-arc-v2-2-5c97a865b276@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Asahi Lina
1edd03378e rust: sync: arc: Implement Arc<dyn Any + Send + Sync>::downcast()
This mirrors the standard library's alloc::sync::Arc::downcast().

Based on the Rust standard library implementation, ver 1.62.0,
licensed under "Apache-2.0 OR MIT", from:

    https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src

For copyright details, please see:

    https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT

Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-arc-v2-1-5c97a865b276@asahilina.net
[ Moved `mod std_vendor;` up. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 23:55:43 +02:00
Asahi Lina
39867fec28 rust: macros: Allow specifying multiple module aliases
Modules can (and usually do) have multiple alias tags, in order to
specify multiple possible device matches for autoloading. Allow this by
changing the alias ModuleInfo field to an Option<Vec<String>>.

Note: For normal device IDs this is autogenerated by modpost (which is
not properly integrated with Rust support yet), so it is useful to be
able to manually add device match aliases for now, and should still be
useful in the future for corner cases that modpost does not handle.

This pulls in the expect_group() helper from the rfl/rust branch
(with credit to authors).

Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: Finn Behrens <me@kloenk.dev>
Signed-off-by: Finn Behrens <me@kloenk.dev>
Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-macros-v2-1-7396e8b7018d@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 23:55:43 +02:00
Miguel Ojeda
318c3cc8e1 rust: alloc: vec: Add some try_* methods we need
Add some missing fallible methods that we need.

They are all marked as:

    #[stable(feature = "kernel", since = "1.0.0")]

for easy identification.

Lina: Extracted from commit 487d7578bd03 ("rust: alloc: add some `try_*`
methods we need") in rust-for-linux/rust.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://github.com/Rust-for-Linux/linux/commit/487d7578bd03
Link: https://lore.kernel.org/r/20230224-rust-vec-v1-4-733b5b5a57c5@asahilina.net
[ Match the non-fallible methods from version 1.62.0, since those
  in commit 487d7578bd03 were written for 1.54.0-beta.1. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 23:55:43 +02:00
Asahi Lina
3dcb652a3a rust: Add SPDX headers to alloc::vec::{spec_extend, set_len_on_drop}
Add the missing SPDX headers to these modules, which were just imported
from the Rust stdlib. Doing this in a separate commit makes it easier to
audit that the files have not been modified in the original import.

See the preceding two commits for attribution and licensing details.

Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-vec-v1-3-733b5b5a57c5@asahilina.net
[ Reworded for typo. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 23:55:19 +02:00
Asahi Lina
ae12ae1372 rust: Import upstream alloc::vec::spec_extend module
This is a subset of the Rust standard library `alloc` crate,
version 1.62.0, licensed under "Apache-2.0 OR MIT", from:

    https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src

The file is copied as-is, with no modifications whatsoever
(not even adding the SPDX identifiers).

For copyright details, please see:

    https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT

Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-vec-v1-2-733b5b5a57c5@asahilina.net
[ Import version 1.62.0 instead, to match the one in mainline. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 05:21:33 +02:00
Asahi Lina
65b571afdf rust: Import upstream alloc::vec::set_len_on_drop module
This is a subset of the Rust standard library `alloc` crate,
version 1.62.0, licensed under "Apache-2.0 OR MIT", from:

    https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src

The file is copied as-is, with no modifications whatsoever
(not even adding the SPDX identifiers).

For copyright details, please see:

    https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT

Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-vec-v1-1-733b5b5a57c5@asahilina.net
[ Import version 1.62.0 instead, to match the one in mainline. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 05:21:26 +02:00
Asahi Lina
3c01a424a3 rust: Enable the new_uninit feature for kernel and driver crates
The unstable new_uninit feature enables various library APIs to create
uninitialized containers, such as `Box::assume_init()`. This is
necessary to build abstractions that directly initialize memory at the
target location, instead of doing copies through the stack.

Will be used by the DRM scheduler abstraction in the kernel crate, and
by field-wise initialization (e.g. using `place!()` or a future
replacement macro which may itself live in `kernel`) in driver crates.

Link: https://github.com/Rust-for-Linux/linux/issues/879
Link: https://github.com/Rust-for-Linux/linux/issues/2
Link: https://github.com/rust-lang/rust/issues/63291
Signed-off-by: Asahi Lina <lina@asahilina.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Link: https://lore.kernel.org/r/20230224-rust-new_uninit-v1-1-c951443d9e26@asahilina.net
[ Reworded to use `Link` tags. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 05:21:15 +02:00
Boqun Feng
00140a8308 rust: sync: impl {Debug,Display} for {Unique,}Arc
This allows printing the inner data of `Arc` and its friends if the
inner data implements `Display` or `Debug`. It's useful for logging and
debugging purpose.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Link: https://lore.kernel.org/r/20230207185216.1314638-2-boqun.feng@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 05:05:39 +02:00
Vincenzo Palazzo
1c5f054f0b rust: build: Fix grep warning
Fix grep warning during the build, with GNU grep 3.8
with the following command

`grep -v '^\#\|^$$' rust/bindgen_parameters`

I see the following warning

```
grep: warning: stray \ before #

--opaque-type xregs_state
--opaque-type desc_struct
--opaque-type arch_lbr_state
--opaque-type local_apic

--opaque-type x86_msi_data
--opaque-type x86_msi_addr_lo

--opaque-type kunit_try_catch

--opaque-type spinlock

--no-doc-comments
```

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Tested-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-07 00:53:40 +02:00
David Gow
c682e4c37d rust: kernel: Mark rust_fmt_argument as extern "C"
The rust_fmt_argument function is called from printk() to handle the %pA
format specifier.

Since it's called from C, we should mark it extern "C" to make sure it's
ABI compatible.

Cc: stable@vger.kernel.org
Fixes: 247b365dc8 ("rust: add `kernel` crate")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
[Applied `rustfmt`]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-06 23:11:04 +02:00
Patrick Blass
88e8c2ec4a rust: str: fix requierments->requirements typo
Fix a trivial spelling error in the `rust/kernel/str.rs` file.

Fixes: 247b365dc8 ("rust: add `kernel` crate")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/978
Signed-off-by: Patrick Blass <patrickblass@mailbox.org>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
[Reworded slightly]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-06 21:55:12 +02:00
Linus Torvalds
34c108a02c Rust fixes for 6.3-rc1
A single build error fix: there was a change during the merge window
 to a C header parsed by the Rust bindings generator, introducing a
 type that it does not handle well. The fix tells the generator to
 treat the type as opaque (for now).
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Merge tag 'rust-fixes-6.3-rc1' of https://github.com/Rust-for-Linux/linux

Pull Rust fix from Miguel Ojeda:
 "A single build error fix: there was a change during the merge window
  to a C header parsed by the Rust bindings generator, introducing a
  type that it does not handle well.

  The fix tells the generator to treat the type as opaque (for now)"

* tag 'rust-fixes-6.3-rc1' of https://github.com/Rust-for-Linux/linux:
  rust: bindgen: Add `alt_instr` as opaque type
2023-03-03 14:51:15 -08:00
Arnaldo Carvalho de Melo
3098cb655e rust: bindgen: Add alt_instr as opaque type
To address this build error:

    BINDGEN rust/bindings/bindings_generated.rs
    BINDGEN rust/bindings/bindings_helpers_generated.rs
    EXPORTS rust/exports_core_generated.h
    RUSTC P rust/libmacros.so
    RUSTC L rust/compiler_builtins.o
    RUSTC L rust/alloc.o
    RUSTC L rust/bindings.o
    RUSTC L rust/build_error.o
    EXPORTS rust/exports_alloc_generated.h
  error[E0588]: packed type cannot transitively contain a `#[repr(align)]` type
       --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10094:1
        |
  10094 | / pub struct alt_instr {
  10095 | |     pub instr_offset: s32,
  10096 | |     pub repl_offset: s32,
  10097 | |     pub __bindgen_anon_1: alt_instr__bindgen_ty_1,
  10098 | |     pub instrlen: u8_,
  10099 | |     pub replacementlen: u8_,
  10100 | | }
        | |_^
        |
  note: `alt_instr__bindgen_ty_1__bindgen_ty_1` has a `#[repr(align)]` attribute
       --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10111:1
        |
  10111 | / pub struct alt_instr__bindgen_ty_1__bindgen_ty_1 {
  10112 | |     pub _bitfield_1: __BindgenBitfieldUnit<[u8; 4usize], u16>,
  10113 | | }
        | |_^
  note: `alt_instr` contains a field of type `alt_instr__bindgen_ty_1`
       --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10097:9
        |
  10097 |     pub __bindgen_anon_1: alt_instr__bindgen_ty_1,
        |         ^^^^^^^^^^^^^^^^
  note: ...which contains a field of type `alt_instr__bindgen_ty_1__bindgen_ty_1`
       --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10104:9
        |
  10104 |     pub __bindgen_anon_1: alt_instr__bindgen_ty_1__bindgen_ty_1,
        |         ^^^^^^^^^^^^^^^^

  error: aborting due to previous error

  For more information about this error, try `rustc --explain E0588`.
  make[1]: *** [rust/Makefile:389: rust/bindings.o] Error 1
  make: *** [Makefile:1293: prepare] Error 2

Cc: Derek Barbosa <debarbos@redhat.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fixes: 5d1dd961e7 ("x86/alternatives: Add alt_instr.flags")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-03-02 22:44:15 +01:00
Linus Torvalds
498a1cf902 Kbuild updates for v6.3
- Change V=1 option to print both short log and full command log.
 
  - Allow V=1 and V=2 to be combined as V=12.
 
  - Make W=1 detect wrong .gitignore files.
 
  - Tree-wide cleanups for unused command line arguments passed to Clang.
 
  - Stop using -Qunused-arguments with Clang.
 
  - Make scripts/setlocalversion handle only correct release tags instead
    of any arbitrary annotated tag.
 
  - Create Debian and RPM source packages without cleaning the source tree.
 
  - Various cleanups for packaging.
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Merge tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Change V=1 option to print both short log and full command log

 - Allow V=1 and V=2 to be combined as V=12

 - Make W=1 detect wrong .gitignore files

 - Tree-wide cleanups for unused command line arguments passed to Clang

 - Stop using -Qunused-arguments with Clang

 - Make scripts/setlocalversion handle only correct release tags instead
   of any arbitrary annotated tag

 - Create Debian and RPM source packages without cleaning the source
   tree

 - Various cleanups for packaging

* tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (74 commits)
  kbuild: rpm-pkg: remove unneeded KERNELRELEASE from modules/headers_install
  docs: kbuild: remove description of KBUILD_LDS_MODULE
  .gitattributes: use 'dts' diff driver for *.dtso files
  kbuild: deb-pkg: improve the usability of source package
  kbuild: deb-pkg: fix binary-arch and clean in debian/rules
  kbuild: tar-pkg: use tar rules in scripts/Makefile.package
  kbuild: make perf-tar*-src-pkg work without relying on git
  kbuild: deb-pkg: switch over to source format 3.0 (quilt)
  kbuild: deb-pkg: make .orig tarball a hard link if possible
  kbuild: deb-pkg: hide KDEB_SOURCENAME from Makefile
  kbuild: srcrpm-pkg: create source package without cleaning
  kbuild: rpm-pkg: build binary packages from source rpm
  kbuild: deb-pkg: create source package without cleaning
  kbuild: add a tool to list files ignored by git
  Documentation/llvm: add Chimera Linux, Google and Meta datacenters
  setlocalversion: use only the correct release tag for git-describe
  setlocalversion: clean up the construction of version output
  .gitignore: ignore *.cover and *.mbx
  kbuild: remove --include-dir MAKEFLAG from top Makefile
  kbuild: fix trivial typo in comment
  ...
2023-02-26 11:53:25 -08:00
Linus Torvalds
69adb0bcb8 Rust changes for v6.3
More core additions, getting closer to a point where the first Rust
 modules can be upstreamed. The major ones being:
 
 - Sync: new types 'Arc', 'ArcBorrow' and 'UniqueArc'.
 
 - Types: new trait 'ForeignOwnable' and new type 'ScopeGuard'.
 
 There is also a substantial removal in terms of lines:
 
 - 'alloc' crate: remove the 'borrow' module (type 'Cow' and trait
   'ToOwned').
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Merge tag 'rust-6.3' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "More core additions, getting closer to a point where the first Rust
  modules can be upstreamed. The major ones being:

   - Sync: new types 'Arc', 'ArcBorrow' and 'UniqueArc'.

   - Types: new trait 'ForeignOwnable' and new type 'ScopeGuard'.

  There is also a substantial removal in terms of lines:

   - 'alloc' crate: remove the 'borrow' module (type 'Cow' and trait
     'ToOwned')"

* tag 'rust-6.3' of https://github.com/Rust-for-Linux/linux:
  rust: delete rust-project.json when running make clean
  rust: MAINTAINERS: Add the zulip link
  rust: types: implement `ForeignOwnable` for `Arc<T>`
  rust: types: implement `ForeignOwnable` for the unit type
  rust: types: implement `ForeignOwnable` for `Box<T>`
  rust: types: introduce `ForeignOwnable`
  rust: types: introduce `ScopeGuard`
  rust: prelude: prevent doc inline of external imports
  rust: sync: add support for dispatching on Arc and ArcBorrow.
  rust: sync: introduce `UniqueArc`
  rust: sync: allow type of `self` to be `ArcBorrow<T>`
  rust: sync: introduce `ArcBorrow`
  rust: sync: allow coercion from `Arc<T>` to `Arc<U>`
  rust: sync: allow type of `self` to be `Arc<T>` or variants
  rust: sync: add `Arc` for ref-counted allocations
  rust: compiler_builtins: make stubs non-global
  rust: alloc: remove the `borrow` module (`ToOwned`, `Cow`)
2023-02-20 10:40:42 -08:00
Wedson Almeida Filho
0c7ae43257 rust: types: implement ForeignOwnable for Arc<T>
This allows us to hand ownership of Rust ref-counted objects to
the C side of the kernel.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Alice Ferrazzi <alice.ferrazzi@miraclelinux.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-02-07 11:24:24 +01:00
Wedson Almeida Filho
7118594466 rust: types: implement ForeignOwnable for the unit type
This allows us to use the unit type `()` when we have no object whose
ownership must be managed but one implementing the `ForeignOwnable`
trait is needed.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-02-01 13:24:36 +01:00
Wedson Almeida Filho
26949bac1e rust: types: implement ForeignOwnable for Box<T>
This allows us to hand ownership of Rust dynamically allocated
objects to the C side of the kernel.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Alice Ferrazzi <alice.ferrazzi@miraclelinux.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-02-01 13:24:19 +01:00
Wedson Almeida Filho
0fc4424d24 rust: types: introduce ForeignOwnable
It was originally called `PointerWrapper`. It is used to convert
a Rust object to a pointer representation (void *) that can be
stored on the C side, used, and eventually returned to Rust.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-02-01 13:24:07 +01:00
Wedson Almeida Filho
4d4692a2ff rust: types: introduce ScopeGuard
This allows us to run some code when the guard is dropped (e.g.,
implicitly when it goes out of scope). We can also prevent the
guard from running by calling its `dismiss()` method.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-02-01 00:14:01 +01:00
Masahiro Yamada
c83b16cefd kbuild: rust: move rust/target.json to scripts/
scripts/ is a better place to generate files used treewide.

With target.json moved to scripts/, you do not need to add target.json
to no-clean-files or MRPROPER_FILES.

'make clean' does not visit scripts/, but 'make mrproper' does.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-22 23:43:33 +09:00
Masahiro Yamada
2185242fad kbuild: remove sed commands after rustc rules
rustc may put comments in dep-info, so sed is used to drop them before
passing it to fixdep.

Now that fixdep can remove comments, Makefiles do not need to run sed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2023-01-22 23:43:33 +09:00
Masahiro Yamada
295d8398c6 kbuild: specify output names separately for each emission type from rustc
In Kbuild, two different rules must not write to the same file, but
it happens when compiling rust source files.

For example, set CONFIG_SAMPLE_RUST_MINIMAL=m and run the following:

  $ make -j$(nproc) samples/rust/rust_minimal.o samples/rust/rust_minimal.rsi \
                    samples/rust/rust_minimal.s samples/rust/rust_minimal.ll
    [snip]
    RUSTC [M] samples/rust/rust_minimal.o
    RUSTC [M] samples/rust/rust_minimal.rsi
    RUSTC [M] samples/rust/rust_minimal.s
    RUSTC [M] samples/rust/rust_minimal.ll
  mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory
  make[3]: *** [scripts/Makefile.build:334: samples/rust/rust_minimal.ll] Error 1
  make[3]: *** Waiting for unfinished jobs....
  mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory
  make[3]: *** [scripts/Makefile.build:309: samples/rust/rust_minimal.o] Error 1
  mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory
  make[3]: *** [scripts/Makefile.build:326: samples/rust/rust_minimal.s] Error 1
  make[2]: *** [scripts/Makefile.build:504: samples/rust] Error 2
  make[1]: *** [scripts/Makefile.build:504: samples] Error 2
  make: *** [Makefile:2008: .] Error 2

The reason for the error is that 4 threads running in parallel renames
the same file, samples/rust/rust_minimal.d.

This does not happen when compiling C or assembly files because
-Wp,-MMD,$(depfile) explicitly specifies the dependency filepath.
$(depfile) is a unique path for each target.

Currently, rustc is only given --out-dir and --emit=<list-of-types>
So, all the rust build rules output the dep-info into the default
<CRATE_NAME>.d, which causes the path conflict.

Fortunately, the --emit option is able to specify the output path
individually, with the form --emit=<type>=<path>.

Add --emit=dep-info=$(depfile) to the common part. Also, remove the
redundant --out-dir because the output path is specified for each type.

The code gets much cleaner because we do not need to rename *.d files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2023-01-22 23:43:33 +09:00
Finn Behrens
dec1df547d rust: prelude: prevent doc inline of external imports
This shows exactly where the items are from, previously the items from
macros, alloc and core were shown as a declaration from the kernel crate,
this shows the correct path.

Link: https://github.com/rust-lang/rust/issues/106713
Signed-off-by: Finn Behrens <fin@nyantec.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
[Reworded to add Link, fixed two typos and comment style]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 23:49:46 +01:00
Wedson Almeida Filho
0748424aba rust: sync: add support for dispatching on Arc and ArcBorrow.
Trait objects (`dyn T`) require trait `T` to be "object safe". One of
the requirements for "object safety" is that the receiver have one of
the allowed types. This commit adds `Arc<T>` and `ArcBorrow<'_, T>` to
the list of allowed types.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 23:48:06 +01:00
Wedson Almeida Filho
70e42ebbf6 rust: sync: introduce UniqueArc
Since `Arc<T>` does not allow mutating `T` directly (i.e., without inner
mutability), it is currently not possible to do some initialisation of
`T` post construction but before being shared.

`UniqueArc<T>` addresses this problem essentially being an `Arc<T>` that
has a refcount of 1 and is therefore writable. Once initialisation is
completed, it can be transitioned (without failure paths) into an
`Arc<T>`.

Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 23:48:06 +01:00
Wedson Almeida Filho
92a655ae00 rust: sync: allow type of self to be ArcBorrow<T>
This allows associated functions whose `self` argument has
`ArcBorrow<T>` as their type. This, in turn, allows callers to use the
dot syntax to make calls.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 23:48:06 +01:00
Wedson Almeida Filho
17f671602c rust: sync: introduce ArcBorrow
This allows us to create references to a ref-counted allocation without
double-indirection and that still allow us to increment the refcount to
a new `Arc<T>`.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 23:47:57 +01:00
Wedson Almeida Filho
f75cb6fce4 rust: sync: allow coercion from Arc<T> to Arc<U>
The coercion is only allowed if `U` is a compatible dynamically-sized
type (DST). For example, if we have some type `X` that implements trait
`Y`, then this allows `Arc<X>` to be coerced into `Arc<dyn Y>`.

Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 22:20:24 +01:00
Wedson Almeida Filho
53528772fb rust: sync: allow type of self to be Arc<T> or variants
This allows associated functions whose `self` argument has `Arc<T>` or
variants as their type. This, in turn, allows callers to use the dot
syntax to make calls.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 22:20:18 +01:00
Wedson Almeida Filho
9dc0436550 rust: sync: add Arc for ref-counted allocations
This is a basic implementation of `Arc` backed by C's `refcount_t`. It
allows Rust code to idiomatically allocate memory that is ref-counted.

Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 22:20:03 +01:00
Gary Guo
cb7d9defda rust: compiler_builtins: make stubs non-global
Currently we define a number of stubs for compiler-builtin intrinsics
that compiled libcore generates. The defined stubs are weak so they will
not conflict with genuine implementation of these intrinsics, but their
effect is global and will cause non-libcore code that accidently
generate these intrinsics calls compile and bug on runtime.

Instead of defining a stub that can affect all code, this patch uses
objcopy's `--redefine-sym` flag to redirect these calls (from libcore
only) to a prefixed version (e.g. redirect `__multi3` to `__rust_multi3`),
so we can define panciking stubs that are only visible to libcore.

This patch was previously discussed on GitHub [1]. This approach was also
independently proposed by Nick Desaulniers in [2].

Link: https://github.com/Rust-for-Linux/linux/pull/779 [1]
Link: https://lore.kernel.org/lkml/CAKwvOdkc0Qhwu=gfe1+H23TnAa6jnO6A3ZCO687dH6mSrATmDA@mail.gmail.com/
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 21:04:34 +01:00
Miguel Ojeda
8909a80e3f rust: alloc: remove the borrow module (ToOwned, Cow)
The `Cow` type [1] requires that its generic parameter type implements
the `ToOwned` trait [2], which provides a method to create owned data
from borrowed data, usually by cloning.

However, it is infallible, and thus in most cases it is not useful for
the kernel. [3]

Therefore, introduce `cfg(no_borrow)` to remove the `borrow` module
(which contains `ToOwned` and `Cow`) from `alloc`.

Link: https://doc.rust-lang.org/alloc/borrow/enum.Cow.html [1]
Link: https://doc.rust-lang.org/alloc/borrow/trait.ToOwned.html [2]
Link: https://lore.kernel.org/rust-for-linux/20221204103153.117675b1@GaryWorkstation/ [3]
Cc: Gary Guo <gary@garyguo.net>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Finn Behrens <fin@nyantec.com>
2023-01-16 21:03:49 +01:00
Miguel Ojeda
6618d69aa1 rust: print: avoid evaluating arguments in pr_* macros in unsafe blocks
At the moment it is possible to perform unsafe operations in
the arguments of `pr_*` macros since they are evaluated inside
an `unsafe` block:

    let x = &10u32 as *const u32;
    pr_info!("{}", *x);

In other words, this is a soundness issue.

Fix it so that it requires an explicit `unsafe` block.

Reported-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reported-by: Domen Puncer Kugler <domen.puncerkugler@nccgroup.com>
Link: https://github.com/Rust-for-Linux/linux/issues/479
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2023-01-16 00:54:35 +01:00
Wedson Almeida Filho
b9ecf9b9ac rust: types: add Opaque type
Add the `Opaque` type, which is meant to be used with FFI objects
that are never interpreted by Rust code, e.g.:

    struct Waiter {
        completion: Opaque<bindings::completion>,
        next: *mut Waiter,
    }

It has the advantage that the objects don't have to be
zero-initialised before calling their init functions, making
the code performance closer to C.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Wedson Almeida Filho
ba20915bae rust: types: add Either type
Introduce the new `types` module of the `kernel` crate with
`Either` as its first type.

`Either<L, R>` is a sum type that always holds either a value
of type `L` (`Left` variant) or `R` (`Right` variant).

For instance:

    struct Executor {
        queue: Either<BoxedQueue, &'static Queue>,
    }

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Gary Guo
0f595bab9d rust: build_assert: add build_{error,assert}! macros
Add the `build_error!` and `build_assert!` macros which leverage
the previously introduced `build_error` crate. Do so in a new
module, called `build_assert`.

The former fails the build if the code path calling it can possibly
be executed. The latter asserts that a boolean expression is `true`
at compile time.

In particular, `build_assert!` can be used in some contexts where
`static_assert!` cannot:

    fn f1<const N: usize>() {
        static_assert!(N > 1);` // Error.
        build_assert!(N > 1);   // Build-time check.
        assert!(N > 1);         // Run-time check.
    }

    #[inline]
    fn f2(n: usize) {
        static_assert!(n > 1);  // Error.
        build_assert!(n > 1);   // Build-time check.
        assert!(n > 1);         // Run-time check.
    }

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Gary Guo
ecaa6ddff2 rust: add build_error crate
The `build_error` crate provides a function `build_error` which
will panic at compile-time if executed in const context and,
by default, will cause a build error if not executed at compile
time and the optimizer does not optimise away the call.

The `CONFIG_RUST_BUILD_ASSERT_ALLOW` kernel option allows to
relax the default build failure and convert it to a runtime
check. If the runtime check fails, `panic!` will be called.

Its functionality will be exposed to users as a couple macros in
the `kernel` crate in the following patch, thus some documentation
here refers to them for simplicity.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Miguel Ojeda
ef9e37973c rust: static_assert: add static_assert! macro
Add the `static_assert!` macro, which is a compile-time assert, similar
to the C11 `_Static_assert` and C++11 `static_assert` declarations [1,2].
Do so in a new module, called `static_assert`.

For instance:

    static_assert!(42 > 24);
    static_assert!(core::mem::size_of::<u8>() == 1);

    const X: &[u8] = b"bar";
    static_assert!(X[1] == b'a');

    const fn f(x: i32) -> i32 {
        x + 2
    }
    static_assert!(f(40) == 42);

Link: https://en.cppreference.com/w/c/language/_Static_assert [1]
Link: https://en.cppreference.com/w/cpp/language/static_assert [2]
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Niklas Mohrin
bee1688940 rust: std_vendor: add dbg! macro based on std's one
The Rust standard library has a really handy macro, `dbg!` [1,2].
It prints the source location (filename and line) along with the raw
source code that is invoked with and the `Debug` representation
of the given expression, e.g.:

    let a = 2;
    let b = dbg!(a * 2) + 1;
    //      ^-- prints: [src/main.rs:2] a * 2 = 4
    assert_eq!(b, 5);

Port the macro over to the `kernel` crate inside a new module
called `std_vendor`, using `pr_info!` instead of `eprintln!` and
make the rules about committing uses of `dbg!` into version control
more concrete (i.e. tailored for the kernel).

Since the source code for the macro is taken from the standard
library source (with only minor adjustments), the new file is
licensed under `Apache 2.0 OR MIT`, just like the original [3,4].

Link: https://doc.rust-lang.org/std/macro.dbg.html [1]
Link: https://github.com/rust-lang/rust/blob/master/library/std/src/macros.rs#L212 [2]
Link: https://github.com/rust-lang/rust/blob/master/library/std/Cargo.toml [3]
Link: https://github.com/rust-lang/rust/blob/master/COPYRIGHT [4]
Signed-off-by: Niklas Mohrin <dev@niklasmohrin.de>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Wedson Almeida Filho
ef32054942 rust: str: add fmt! macro
Add the `fmt!` macro, which is a convenience alias for the Rust
`core::format_args!` macro.

For instance, it may be used to create a `CString`:

    CString::try_from_fmt(fmt!("{}{}", "abc", 42))?

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00
Wedson Almeida Filho
65e1e497f6 rust: str: add CString type
Add the `CString` type, which is an owned string that is guaranteed
to have exactly one `NUL` byte at the end, i.e. the owned equivalent
to `CStr` introduced earlier.

It is used for interoperability with kernel APIs that take C strings.

In order to do so, implement the `RawFormatter::new()` constructor
and the `RawFormatter::bytes_written()` method as well.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Wedson Almeida Filho
fffed679ee rust: str: add Formatter type
Add the `Formatter` type, which leverages `RawFormatter`,
but fails if callers attempt to write more than will fit
in the buffer.

In order to so, implement the `RawFormatter::from_buffer()`
constructor as well.

Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
b18cb00e5a rust: str: add c_str! macro
Add `c_str!`, which is a convenience macro that creates a new `CStr`
from a string literal.

It is designed to be similar to a `str` in usage, and it is usable
in const contexts, for instance:

    const X: &CStr = c_str!("Example");

Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Milan Landaverde
985f1f09bf rust: str: add CStr unit tests
Add unit tests for `CStr::from_bytes_with_nul()` and
`CStr::from_bytes_with_nul_unchecked()`.

These serve as an example of the first unit tests for Rust code
(i.e. different from documentation tests).

Signed-off-by: Milan Landaverde <milan@mdaverde.com>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
c07e67bd2d rust: str: implement several traits for CStr
Implement `Debug`, `Display`, `Deref` (into `BStr`), `AsRef<BStr>`
and a set of `Index<...>` traits.

This makes it `CStr` more convenient to use (and closer to `str`).

Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Morgan Bartlett <mjmouse9999@gmail.com>
Signed-off-by: Morgan Bartlett <mjmouse9999@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
d126d23801 rust: str: add CStr type
Add the `CStr` type, which is a borrowed string that is guaranteed
to have exactly one `NUL` byte, which is at the end.

It is used for interoperability with kernel APIs that take C strings.

Add it to the prelude too.

Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
650ec51561 rust: str: add b_str! macro
Add the `b_str!` macro, which creates a new `BStr` from
a string literal.

It is usable in const contexts, for instance:

    const X: &BStr = b_str!("Example");

Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
7c59774646 rust: str: add BStr type
Add the `BStr` type, which is a byte string without UTF-8
validity guarantee.

It is simply an alias to `[u8]`, but has a more evident
semantical meaning.

Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Miguel Ojeda
feadd06287 rust: alloc: add Vec::try_with_capacity{,_in}() constructors
Add `Vec::try_with_capacity()` and `Vec::try_with_capacity_in()` as
the fallible versions of `Vec::with_capacity()` and
`Vec::with_capacity_in()`, respectively.

The implementations follow the originals and use the previously
added `RawVec::try_with_capacity_in()`.

In turn, `Vec::try_with_capacity()` will be used to implement
the `CString` type (which wraps a `Vec<u8>`) in a later patch.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Miguel Ojeda
51d3a25ab3 rust: alloc: add RawVec::try_with_capacity_in() constructor
Add the `RawVec::try_with_capacity_in()` constructor as the fallible
version of `RawVec::with_capacity_in()`.

The implementation follows the original.

The infallible constructor is implemented in terms of the private
`RawVec::allocate_in()` constructor, thus also add the private
`RawVec::try_allocate_in()` constructor following the other.

It will be used to implement `Vec::try_with_capacity{,_in}()` in
the next patch.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Wedson Almeida Filho
25d176a4fa rust: prelude: add error::code::* constant items
It is convenient to have all the `Error` constant items (such as
`EINVAL`) available as-is everywhere (i.e. for code using the kernel
prelude such as kernel modules).

Therefore, add all of them to the prelude.

For instance, this allows to write `Err(EINVAL)` to create
a kernel `Result`:

    fn f() -> Result<...> {
        ...
        Err(EINVAL)
    }

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Wedson Almeida Filho
76e2c2d9a2 rust: error: add From implementations for Error
Add a set of `From` implementations for the `Error` kernel type.

These implementations allow to easily convert from standard Rust
error types to the usual kernel errors based on one of the `E*`
integer codes.

On top of that, the question mark Rust operator (`?`) implicitly
performs a conversion on the error value using the `From` trait
when propagating. Thus it is extra convenient to use.

For instance, a kernel function that needs to convert a `i64` into
a `i32` and to bubble up the error as a kernel error may write:

    fn f(x: i64) -> Result<...> {
        ...
        let y = i32::try_from(x)?;
        ...
    }

which will transform the `TryFromIntError` into an `Err(EINVAL)`.

Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Nándor István Krácser <bonifaido@gmail.com>
Signed-off-by: Nándor István Krácser <bonifaido@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Viktor Garske
266def2a0f rust: error: add codes from errno-base.h
Only a few codes were added so far. With the `declare_err!`
macro in place, add the remaining ones (which is most of them)
from `include/uapi/asm-generic/errno-base.h`.

Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Viktor Garske <viktor@v-gar.de>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Finn Behrens
4b0c68bd0d rust: error: declare errors using macro
Add a macro to declare errors, which simplifies the work needed to
add each one, avoids repetition of the code and makes it easier to
change the way they are declared.

Signed-off-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
b13c9880f9 rust: macros: take string literals in module!
Instead of taking binary string literals, take string ones instead,
making it easier for users to define a module, i.e. instead of
calling `module!` like:

    module! {
        ...
        name: b"rust_minimal",
        ...
    }

now it is called as:

    module! {
        ...
        name: "rust_minimal",
        ...
    }

Module names, aliases and license strings are restricted to
ASCII only. However, the author and the description allows UTF-8.

For simplicity (avoid parsing), escape sequences and raw string
literals are not yet handled.

Link: https://github.com/Rust-for-Linux/linux/issues/252
Link: https://lore.kernel.org/lkml/YukvvPOOu8uZl7+n@yadro.com/
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
b44becc5ee rust: macros: add #[vtable] proc macro
This procedural macro attribute provides a simple way to declare
a trait with a set of operations that later users can partially
implement, providing compile-time `HAS_*` boolean associated
constants that indicate whether a particular operation was overridden.

This is useful as the Rust counterpart to structs like
`file_operations` where some pointers may be `NULL`, indicating
an operation is not provided.

For instance:

    #[vtable]
    trait Operations {
        fn read(...) -> Result<usize> {
            Err(EINVAL)
        }

        fn write(...) -> Result<usize> {
            Err(EINVAL)
        }
    }

    #[vtable]
    impl Operations for S {
        fn read(...) -> Result<usize> {
            ...
        }
    }

    assert_eq!(<S as Operations>::HAS_READ, true);
    assert_eq!(<S as Operations>::HAS_WRITE, false);

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Sergio González Collado <sergio.collado@gmail.com>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Björn Roy Baron
60f18c225f rust: macros: add concat_idents! proc macro
This macro provides similar functionality to the unstable feature
`concat_idents` without having to rely on it.

For instance:

    let x_1 = 42;
    let x_2 = concat_idents!(x, _1);
    assert!(x_1 == x_2);

It has different behavior with respect to macro hygiene. Unlike
the unstable `concat_idents!` macro, it allows, for example,
referring to local variables by taking the span of the second
macro as span for the output identifier.

Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:04 +01:00
Miguel Ojeda
fc6c7cac83 rust: print: add pr_cont! macro
This level is a bit different from the rest since it does not
pass the module name to the `_printk()` call.

Thus add a new parameter to the general `print_macro!` to
handle it differently.

Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Sergio González Collado <sergio.collado@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-01 20:12:44 +01:00
Miguel Ojeda
4c7f949906 rust: print: add more pr_*! levels
Currently, only `pr_info!` (for the minimal sample) and
`pr_emerg!` (for the panic handler) are there.

Add the other levels as new macros, i.e. `pr_alert!`, `pr_crit!`,
`pr_err!`, `pr_warn!`, `pr_notice!` and `pr_debug!`.

Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Sergio Gonzalez Collado <sergio.collado@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-01 20:12:14 +01:00
Miguel Ojeda
474be44555 rust: prelude: split re-exports into groups
Split the prelude re-exports into groups: first the ones coming
from the `core` crate, then `alloc`, then our own crates and
finally the ones from modules from `kernel` itself (i.e. `super`).

We are doing this manually for the moment, but ideally, long-term,
this could be automated via `rustfmt` with options such as
`group_imports` and `imports_granularity` (both currently unstable).

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-01 20:12:02 +01:00
Miguel Ojeda
2f7ab1267d Kbuild: add Rust support
Having most of the new files in place, we now enable Rust support
in the build system, including `Kconfig` entries related to Rust,
the Rust configuration printer and a few other bits.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Douglas Su <d0u9.su@outlook.com>
Signed-off-by: Douglas Su <d0u9.su@outlook.com>
Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Co-developed-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Co-developed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 09:02:20 +02:00
Miguel Ojeda
8fcbf02492 rust: export generated symbols
All symbols are reexported reusing the `EXPORT_SYMBOL_GPL` macro
from C. The lists of symbols are generated on the fly.

There are three main sets of symbols to distinguish:

  - The ones from the `core` and `alloc` crates (from the Rust
    standard library). The code is licensed as Apache/MIT.

  - The ones from our abstractions in the `kernel` crate.

  - The helpers (already exported since they are not generated).

We export everything as GPL. This ensures we do not mistakenly
expose GPL kernel symbols/features as non-GPL, even indirectly.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:59:52 +02:00
Wedson Almeida Filho
247b365dc8 rust: add kernel crate
The `kernel` crate currently includes all the abstractions that wrap
kernel features written in C.

These abstractions call the C side of the kernel via the generated
bindings with the `bindgen` tool. Modules developed in Rust should
never call the bindings themselves.

In the future, as the abstractions grow in number, we may need
to split this crate into several, possibly following a similar
subdivision in subsystems as the kernel itself and/or moving
the code to the actual subsystems.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Geoffrey Thomas <geofft@ldpreload.com>
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Viktor Garske <viktor@v-gar.de>
Signed-off-by: Viktor Garske <viktor@v-gar.de>
Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Co-developed-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
Signed-off-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
Co-developed-by: Niklas Mohrin <dev@niklasmohrin.de>
Signed-off-by: Niklas Mohrin <dev@niklasmohrin.de>
Co-developed-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Co-developed-by: Morgan Bartlett <mjmouse9999@gmail.com>
Signed-off-by: Morgan Bartlett <mjmouse9999@gmail.com>
Co-developed-by: Maciej Falkowski <m.falkowski@samsung.com>
Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com>
Co-developed-by: Nándor István Krácser <bonifaido@gmail.com>
Signed-off-by: Nándor István Krácser <bonifaido@gmail.com>
Co-developed-by: David Gow <davidgow@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Co-developed-by: John Baublitz <john.m.baublitz@gmail.com>
Signed-off-by: John Baublitz <john.m.baublitz@gmail.com>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:58:24 +02:00
Miguel Ojeda
8326ac05ee rust: add bindings crate
This crate contains the bindings to the C side of the kernel.

Calling C (in general, FFI) is assumed to be unsafe in Rust
and, in many cases, this is accurate. For instance, virtually
all C functions that take a pointer are unsafe since, typically,
it will be dereferenced at some point (and in most cases there
is no way for the callee to check its validity beforehand).

Since one of the goals of using Rust in the kernel is precisely
to avoid unsafe code in "leaf" kernel modules (e.g. drivers),
these bindings should not be used directly by them.

Instead, these bindings need to be wrapped into safe abstractions.
These abstractions provide a safe API that kernel modules can use.
In this way, unsafe code in kernel modules is minimized.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Maciej Falkowski <m.falkowski@samsung.com>
Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com>
Co-developed-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:58:00 +02:00
Miguel Ojeda
1fbde52bde rust: add macros crate
This crate contains all the procedural macros ("proc macros")
shared by all the kernel.

Procedural macros allow to create syntax extensions. They run at
compile-time and can consume as well as produce Rust syntax.

For instance, the `module!` macro that is used by Rust modules
is implemented here. It allows to easily declare the equivalent
information to the `MODULE_*` macros in C modules, e.g.:

    module! {
        type: RustMinimal,
        name: b"rust_minimal",
        author: b"Rust for Linux Contributors",
        description: b"Rust minimal sample",
        license: b"GPL",
    }

Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Matthew Bakhtiari <dev@mtbk.me>
Signed-off-by: Matthew Bakhtiari <dev@mtbk.me>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:58:00 +02:00
Miguel Ojeda
db958dcf88 rust: add compiler_builtins crate
Rust provides `compiler_builtins` as a port of LLVM's `compiler-rt`.
Since we do not need the vast majority of them, we avoid the
dependency by providing our own crate.

Reviewed-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:58:00 +02:00
Miguel Ojeda
057b8d2571 rust: adapt alloc crate to the kernel
This customizes the subset of the Rust standard library `alloc` that
was just imported as-is, mainly by:

  - Adding SPDX license identifiers.

  - Skipping modules (e.g. `rc` and `sync`) via new `cfg`s.

  - Adding fallible (`try_*`) versions of existing infallible methods
    (i.e. returning a `Result` instead of panicking).

    Since the standard library requires stable/unstable attributes,
    these additions are annotated with:

        #[stable(feature = "kernel", since = "1.0.0")]

    Using "kernel" as the feature allows to have the additions
    clearly marked. The "1.0.0" version is just a placeholder.

    (At the moment, only one is needed, but in the future more
    fallible methods will be added).

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Matthew Bakhtiari <dev@mtbk.me>
Signed-off-by: Matthew Bakhtiari <dev@mtbk.me>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:57:01 +02:00
Miguel Ojeda
753dece88d rust: import upstream alloc crate
This is a subset of the Rust standard library `alloc` crate,
version 1.62.0, licensed under "Apache-2.0 OR MIT", from:

    https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src

The files are copied as-is, with no modifications whatsoever
(not even adding the SPDX identifiers).

For copyright details, please see:

    https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT

The next patch modifies these files as needed for use within
the kernel. This patch split allows reviewers to double-check
the import and to clearly see the differences introduced.

Vendoring `alloc`, at least for the moment, allows us to have fallible
allocations support (i.e. the `try_*` versions of methods which return
a `Result` instead of panicking) early on. It also gives a bit more
freedom to experiment with new interfaces and to iterate quickly.

Eventually, the goal is to have everything the kernel needs in
upstream `alloc` and drop it from the kernel tree.

For a summary of work on `alloc` happening upstream, please see:

    https://github.com/Rust-for-Linux/linux/issues/408

The following script may be used to verify the contents:

    for path in $(cd rust/alloc/ && find . -type f -name '*.rs'); do
        curl --silent --show-error --location \
            https://github.com/rust-lang/rust/raw/1.62.0/library/alloc/src/$path \
            | diff --unified rust/alloc/$path - && echo $path: OK
    done

Reviewed-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:57:01 +02:00
Miguel Ojeda
12f577216a rust: add C helpers
Introduces the source file that will contain forwarders to C macros
and inlined functions.

Initially this only contains a single helper, but will gain more as
more functionality is added to the `kernel` crate in the future.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Geoffrey Thomas <geofft@ldpreload.com>
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Maciej Falkowski <m.falkowski@samsung.com>
Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com>
Co-developed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:56:43 +02:00